Hitherto, in a communication environment, value added services have centrally been implemented in a so-called Service Control Point (SCP) using intelligent network (IN). Thus, service creation, management and execution has been centralized to the service control point SCP as a specialized functional entity.
Service scripts provide a means to create and manage value added services in a centralized fashion (which is the benefit of an intelligent network) but distribute fully the service execution (which is a bottleneck of an intelligent network).
Service logic is defined with a script which can be moved between functional elements (FE) in an all-IP network and which is executed in a suitable FE.
Usable script languages can be, for example, CPL (Call Processing Language), SIP Servlets (SIP: Session Initiation Protocol) representing executable instructions which handle SIP messages, or CGI (Common Gateway Interface). However, although the present description refers to the above mentioned script languages, this is only for explanatory purposes and by no way limiting the applicability of the present invention to those script languages. Of course other script languages can be used in connection with the present invention.
More precisely, referring to the Call Processing Language (CPL), CFL is related to IP telephony. IP telephony enables calls and multimedia sessions such as simultaneous video and audio calls to be set-up across IP networks. The CPL is intended to be a simple lightweight, efficient and easy to implement language for IP telephony supplementary service creation. It is intended to be independent of operating systems or signaling protocols such as SIP or H.323. CPL is intended particularly for end-user-defined supplementary service creation. The aim is that these scripts can be defined and provisioned quickly on the spot. Because of this, for the creation of CPL scripts various user friendly techniques such as graphical symbolic editors have been envisioned.
CPL is not related to the creation of end-to-end teleservices such as voice or video calls. Instead it is used for supplementary service creation. By a supplementary service is meant a service that is separately defined to alter in the network the treatment of calls involving certain basic end-to-end services i.e. teleservices and bearer services. For example, supplementary services can affect call routing (e.g. redirect them to different addresses) or screen incoming or outgoing calls.
The CPL language scripts are distributed to the IP telephony servers participating in the handling of the calls that need to be affected using these supplementary services. The scripts are inserted in these servers by the IP telephony network management system, end-user or administrators. There can be several CPL script instances participating to the handling of a given call. The individual script instances are triggered and executed on signalling events conforming to predefined criteria such as caller or callee identification. For example, when there is an incoming call to a subscriber who has defined an incoming call screening script, the script is executed because the callee identification matches.
In general, scripts (service scripts) provide an efficient, portable and powerful tool for executing control instructions in a distributed network. Scripts are for example used in Internet web pages to create different kind of effects for users. A script is transferred (downloaded) from a web server to the local computer and executed there.
Furthermore, up to now the architecture has been open, both in standardization and implementation. However, in order to use scripts for service implementation, some architecture and arrangement must be provided.
Moreover, using CPL scripts in connection with SIP invite methods means to put call processing language (CPL) scripts into SIP invite methods. These can provide a service execution in proxy nodes as specified by the user in an IN network type. Hitherto, however, a SIP client (terminal) added the script to the invite method, thereby resulting in an increased signaling amount.